Why use cumulativeGasUsed instead of gasUsed for calculations?

[codersjj]

see: https://docs.web3js.org/guides/transactions/transactions/#step-4-send-a-transaction-and-review-the-results:~:text=Note%20that%20the,by%20effectiveGasPrice).

effectiveGasPrice is the price per gas at the time of your transaction, so the total gas cost of your transaction is effectiveGasPrice * gasUsed.
gasUsed is the total amount of gas used by this specific transaction.
So, why use cumulativeGasUsed instead of gasUsed for calculations? 😕

[TatyOko28]

You should generally use gasUsed for transaction-specific calculations, as it represents the gas consumed by the current transaction.
cumulativeGasUsed is only relevant if you are analyzing multiple transactions in the same block or debugging gas usage within a complex block context.